Another hidden cost of intermittent renewables: FCAS

Nobody says much about FCAS in public — but it’s become a hot topic among Australia’s energy-nerds and electricity traders. It never used to be a big deal, because we got it at very low cost from huge turbines — from coal, hydro, and gas. Suddenly, it is costing a lot more. As I discovered below, in one month FCAS charges in South Australia rose from $25,000 to $26 million. Wow, just wow.

Take that bitcoin. Something in the financial universe rose even faster.

What is FCAS?

FCAS means”Frequency Control Ancillary Service”. With an AC (or alternating current) system, frequency is everything — the rapid push-pull rhythm that is the power. FCAS is a way of keeping the beat close to the heavenly 50Hz hum (or 60Hz in America and Korea). Network managers cry when things stray outside 49.85Hz or 50.15Hz. So controlling the frequency is a very necessary “other service” supplied by traditional generators, but not so much from intermittent renewables. Large spinning turbines “do” FCAS without a lot of effort. And the cost used to be a tiny fraction of the total electricity bill, but it is rapidly rising in Australia, thanks to the effect of the RET (Renewable Energy Target).

Academia and the ABC finally mention FCAS this week:

Never heard of FCAS? When there is a problem with renewables, the legacy media and academics don’t want to mention it. But when renewables have any benefit, let the free advertising flow. …

Apparently it’s OK to mention it now, because the much loved giant battery of South Australia may have the antidote to the problem that was never said:

In addition, the incredible flexibility of the battery means that it is well suited to participate in the Frequency Control Ancillary Service market. The Frequency Control and Ancillary Service (FCAS) market is less known and understood than the energy market.

Having discussed FCAS in order to rave about The Battery, it was time for a green-academic to say something bad about coal. On cue:

The role of these markets is essentially twofold. First, they provide contingency reserves in case of a major disturbance, such as a large coal generation unit tripping off. The services provide a rapid response to a sudden fall (or rise) in grid frequency.

Those naughty coal turbines, just tripping out like that a couple of times a year (or decade) or so, what ever it is. Let’s not mention that wind and solar are tripping on an hourly basis. ,,,

Exploding costs:

The AEMO warned about the rising costs of FCAS in 2011. Back then they predicted charges for FCAS would rise from $10m to $200m by 2020 and the sole cause was “intermittent energy” and the RET. Even so, this is a small part of the total energy bill which is more like $12-$20 billion.